1. Field of the Invention
The present invention relates to an air-conditioning apparatus which comprises an indoor unit, an outdoor unit, and a compressor incorporated in the indoor unit.
2. Description of the Related Art
An air conditioner has a refrigerating cycle. The refrigerating cycle comprises a compressor, a four-way valve, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger, which are connected by pipes.
To cool a room, the refrigerant supplied from the compressor is passed through the four-way valve, the outdoor heat exchanger, the expansion device and the indoor heat exchanger in the order mentioned, and is fed back into the compressor via the four-way valve. To warm the room, the refrigerant supplied from the compressor is passed through the four-way valve, the indoor heat exchanger, the expansion device and the outdoor heat exchanger, and is fed back into the compressor via the four-way valve.
Generally, the compressor, the four-way valve, the outdoor heat exchanger, the expansion device, and the outdoor fan are incorporated in an outdoor unit, while the indoor heat exchanger and the indoor fan are incorporated in an indoor unit.
Recently a new type of an air conditioner has been developed in which the compressor and the four-way valve are provided in the indoor unit. Incorporating neither a compressor nor a compressor-driving circuit, the outdoor unit can be small. The electric parts in the indoor unit, such as those of the power-supply circuit, can be used to drive the compressor as well, the indoor unit need not have additional electric parts for driving the compressor.
Usually, an air conditioner is installed by the technicians sent from the shop where the user has bought the air conditioner. This is because the indoor and outdoor units must be connected to the commercial AC power supply by high-voltage lines (100 V or more). From a safety point of view it is not recommendable that users should install the air conditioner unless they have been trained to do so.
Jpn. Pat. Appln. KOKAI Publication No. 60-235938 discloses an air conditioner in which the compressor is incorporated in the indoor unit. The indoor and outdoor units of this air conditioner are connected to two receptacles of commercial AC power supplies, respectively. The indoor unit and the outdoor unit are connected together by an AC control line.